Field of the Invention
The instant invention concerns generally animal leashes. The instant invention more specifically concerns retractable animal leashes and specific improvements thereto.
Description of the Related Art
Retractable pet leashes (also referred to herein as retractable “dog leashes”) are well known in the prior art. In operation, retractable pet leashes allow for the effective length of the leash to vary; that is, the leash may be lengthened and shortened as desired by the person operating it.
Retractable pet leashes generally comprise a leash member, on one end of which is an attachment means for attaching the leash member to a pet's collar. The leash member is secured on the opposite end to a spool contained in a housing, the housing further forming in part a handle portion so that the entire device can be held by a person walking the pet. The spool allows for the leash member to be spooled out (i.e., unwound) to increase the effective leash length and to be spooled in (i.e., wound) to shorten the effective leash length. One example of such prior art device is disclosed in U.S. Pat. No. 2,314,504.
Prior art retractable pet leashes include various braking/locking mechanisms; that is, various mechanisms which operate to slow, dampen or stop the spooling of the leash member, in the one or both of the winding and unwinding directions. Two example of such a prior art device are disclosed in U.S. Pat. Pubs. Nos. 2008/0230015 A1 and 2009/0114759 A1.
Prior art retractable leashes suffer significant shortcomings. One primary shortcoming results from device configurations whereby the handle portion of the device is positioned behind the spool mechanism, as shown in the above cited prior art references, as well as, by way of further example, in U.S. Design Pat. No. D235,026. In such configuration, the center of gravity is positioned forward of the user's hand. The force of gravity on the device creates a downward moment about the user's hand and wrist (i.e., it applies a rotational force about that point). This can lead to fatigue, discomfort and stress injuries.
Additionally, in the above-mentioned configuration, the center of gravity of the device is positioned below the line of the user's forearm causing the wrist to typically be held at an angle to the forearm. As a result, forces applied colinearly along the leash member create an upward moment about the user's hand and wrist, tending to “snap” or “jerk” the users hand and wrist upwardly. Such forces are generated for example when a dog pulls, runs, lunges or otherwise rapidly increases the tension on the leash member or suddenly reaches the full extension of the leash member, thereby creating a shock load as the unwinding suddenly ceases. The sudden applied stress on the hand and wrist can easily lead to injury.
Prior art devices generally lack sufficient means of retracting the leash member without pulling the attached dog or walking toward a stationary attached dog. As a result, many users use their free hand to pull the leash member to force it to wind onto the spool. This leads to injuries in the nature of rope burns and cuts when a dog pulls, runs or lunges while the leash member is in the user's free hand.
Among other shortcomings of the prior art are: current retractable leashes tend to break very easily mainly due to the lightweight design of the lock systems and the shock loads produced by the dogs; current retractable leashes have no means of tracking the distance pets have run, (and so a dog owner has no way of knowing if her dog was walked sufficiently in her absence by, for example, a hired dog walker); it can be very difficult to lock a leash quick enough when a dog lunges forward; certain prior art retractable leashes have an on/off lock that locks the leash member at a certain, predetermined distance, however, in such devices the leash member may go slack if the dog gets close to the user; and current retractable leashes are designed for minimal resistance, which gives dogs maximum freedom but does not properly train aggressive dogs that would benefit from a higher resistance.
It is therefore desirable to have a retractable pet leash that solves these various shortcomings of the prior art. Specifically, it is desirable to have a retractable leash that reduces the undesirable transmission of forces to the user such as shock load and other forces detailed above, for example, by providing damped unwinding of the leash member.
It is further desirable to have an improved damping/locking mechanism, including a mechanism that allows for one multiple lock control positions or modes, including: unlock; momentary lock; and detented lock.
It is also desirable to have a retractable pet leash that minimizes or eliminates the problems of the prior art arising from the prior art's placement of the user's hand behind the spool mechanism, i.e., the above-described problems concerning the various rotational forces created about a user's hand and wrist. The desired design would include: a center of gravity located closer to the user's wrist, thereby applying less stress on the wrist; force in alignment with a user's forearm; a stronger grip position; an ergonomic and/or “soft feel” grip. The foregoing improvements, in addition to minimizing the fatigue and possible injury related to the rotational forces of the prior art, would render the retractable leash more appropriate for use by exercising users such as runners.